FINITE ELEMENT ANALYSIS OF SPUR GEAR IN ANSYS
OBJECTIVE: To simulate the stress concentration, total deformation and stress intensity factor for the working of a spur gear.
ABSTRACT: 3 Different materials have been used in the case of spur gear, namely, CAST IRON, CAST BRONZE and CAST STEEL, and the results of the simulation are compared among them.
The materials were added by editing the engineering data on the ANSYS WORKBENCH.
MODEL:
The model used in this simulation project is:
MESH:
Automatic meshing is generated in this simulation.
CONTACT DETAILS:
The following options were selected for contact details:
Type of contact:Frictional
Behaviour:Symmetric
Formulation:Augmented Lagrange
Interface Treatment:Adjust to touch
ANALYSIS SETTINGS:
LEFT GEAR:
RIGHT GEAR:
RESULTS:
CASE 1:
MATERIAL:CAST IRON (DUCTILE):
PROPERTIES:
EQUIVALENT STRESS:
VIDEO LINK:
EQUIVALENT DEFORMATION:
VIDEO LINK:
STRESS INTENSITY FACTOR:
CASE 2:
MATERIAL:CAST STEEL:
PROPERTIES:
EQUIVALENT STRESS:
EQUIVALENT DEFORMATION:
VIDEO LINK:
STRESS INTENSITY FACTOR:
CASE 2:
MATERIAL:CAST BRONZE:
PROPERTIES:
EQUIVALENT STRESS:
EQUIVALENT DEFORMATION:
STRESS INTENSITY FACTOR:
CONCLUSION:
Failure in gear are generally due to cyclic stressing of gear tooth beyond endurance limit and also due to bending fatigue at the root of the gears.
It is seen that total deformation is nearly same for all cases and Equivalent stress is comparatively lower in case of Cast Bronze.
So, considering only the effect of stress concentration and neglecting stress intensity factor, I would go for Cast Bronze as the material for spur gear.
The stress intensity factor is mostly noted for brittle materials and the cast materials are mostly brittle in nature.
Stress Intensity Factor determines the area and magnitude where the crack formation might start taking place.
The value of stress intensity for cast iron ductile is comparatively less and for that reason,it may be in operation even as crack forms since the crack propagation would be less.Hence, sudden failures will not be taking place during operation in this material, which is a very important safety criteria. Therefore, the factor of safety will automatically be less in this case which would eventually be saving a lot of materail cost. It is therefore better to go with cast iron ductile.